Microlenses are used for devices which require an optical focusing apparatus, such as for example cameras of cell phones. Due to miniaturization pressure, the functional regions will become smaller and smaller. The more the microlenses are miniaturized, the more difficult their optically correct production becomes because, at the same time, there is enormous cost pressure for the microlenses to be produced in mass production.
The optical systems can consist of static and/or dynamic convex or concave lenses. The microlenses are embossed either individually on or in a corresponding carrier substrate, or are part of a monolithic wafer. These monolithic wafers therefore constitute carrier-free lens fields. In this respect, “carrier-free” means that the lenses need not be shaped on their own carrier. The lens material is rather deformed along a corresponding surface by an upper and/or lower die into a lens field which is self-supported. The advancing miniaturization is accelerated by the use of these carrier-free lens fields. Carrier-free lens fields on the one hand offer greater flexibility in optical design of thinner lenses and on the other hand high precision in the production. Furthermore, they are produced in one piece, combine lenses and carriers into one another, can be easily handled, transported and connected to one another. The separation of the lens wafers from the corresponding embossing molds or from the embossing dies represents a major technical problem.
An advantage of this invention is a device and a method with which the detachment of the lens wafer is improved, especially in a fully automatic process.
This advantage is achieved with the features of claims 1 and 5. Advantageous developments of the invention are given in the dependent claims. All combinations of at least two of the features given in the specification, the claims and/or the figures also fall within the scope of the invention. At the given value ranges, values within the indicated limits will also be considered to be disclosed as boundary values and will be claimed in any combination.